From: Jean-Jacques Hiblot <jjhiblot@ti.com>
To: <jacek.anaszewski@gmail.com>, <pavel@ucw.cz>,
<robh+dt@kernel.org>, <mark.rutland@arm.com>,
<lee.jones@linaro.org>, <daniel.thompson@linaro.org>
Cc: <dmurphy@ti.com>, <linux-leds@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <dri-devel@lists.freedesktop.org>,
<tomi.valkeinen@ti.com>, Jean-Jacques Hiblot <jjhiblot@ti.com>
Subject: [PATCH v6 1/4] leds: Add of_led_get() and led_put()
Date: Tue, 10 Sep 2019 15:27:31 +0200 [thread overview]
Message-ID: <20190910132734.9544-2-jjhiblot@ti.com> (raw)
In-Reply-To: <20190910132734.9544-1-jjhiblot@ti.com>
From: Tomi Valkeinen <tomi.valkeinen@ti.com>
This patch adds basic support for a kernel driver to get a LED device.
This will be used by the led-backlight driver.
Only OF version is implemented for now, and the behavior is similar to
PWM's of_pwm_get() and pwm_put().
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
drivers/leds/led-class.c | 50 ++++++++++++++++++++++++++++++++++++++++
include/linux/leds.h | 4 ++++
2 files changed, 54 insertions(+)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 159c6caa374b..d4d22f4b5052 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -18,6 +18,7 @@
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <uapi/linux/uleds.h>
+#include <linux/of.h>
#include "leds.h"
static struct class *leds_class;
@@ -213,6 +214,55 @@ static int led_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
+static int led_match_led_node(struct device *led_dev, const void *data)
+{
+ return led_dev->of_node == data;
+}
+
+/**
+ * of_led_get() - request a LED device via the LED framework
+ * @np: device node to get the LED device from
+ * @index: the index of the LED
+ *
+ * Returns the LED device parsed from the phandle specified in the "leds"
+ * property of a device tree node or a negative error-code on failure.
+ */
+struct led_classdev *of_led_get(struct device_node *np, int index)
+{
+ struct device *led_dev;
+ struct led_classdev *led_cdev;
+ struct device_node *led_node;
+
+ led_node = of_parse_phandle(np, "leds", index);
+ if (!led_node)
+ return ERR_PTR(-ENOENT);
+
+ led_dev = class_find_device(leds_class, NULL, led_node,
+ led_match_led_node);
+ of_node_put(led_node);
+
+ if (!led_dev)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ led_cdev = dev_get_drvdata(led_dev);
+
+ if (!try_module_get(led_cdev->dev->parent->driver->owner))
+ return ERR_PTR(-ENODEV);
+
+ return led_cdev;
+}
+EXPORT_SYMBOL_GPL(of_led_get);
+
+/**
+ * led_put() - release a LED device
+ * @led_cdev: LED device
+ */
+void led_put(struct led_classdev *led_cdev)
+{
+ module_put(led_cdev->dev->parent->driver->owner);
+}
+EXPORT_SYMBOL_GPL(led_put);
+
static int match_name(struct device *dev, const void *data)
{
if (!dev_name(dev))
diff --git a/include/linux/leds.h b/include/linux/leds.h
index bee8e3f8dddd..0a71c7cdd191 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -19,6 +19,7 @@
struct device;
struct led_pattern;
+struct device_node;
/*
* LED Core
*/
@@ -145,6 +146,9 @@ extern void devm_led_classdev_unregister(struct device *parent,
extern void led_classdev_suspend(struct led_classdev *led_cdev);
extern void led_classdev_resume(struct led_classdev *led_cdev);
+extern struct led_classdev *of_led_get(struct device_node *np, int index);
+extern void led_put(struct led_classdev *led_cdev);
+
/**
* led_blink_set - set blinking with software fallback
* @led_cdev: the LED to start blinking
--
2.17.1
next prev parent reply other threads:[~2019-09-10 13:28 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-10 13:27 [PATCH v6 0/4] Add a generic driver for LED-based backlight Jean-Jacques Hiblot
2019-09-10 13:27 ` Jean-Jacques Hiblot [this message]
2019-09-10 18:49 ` [PATCH v6 1/4] leds: Add of_led_get() and led_put() Jacek Anaszewski
2019-09-10 13:27 ` [PATCH v6 2/4] leds: Add managed API to get a LED from a device driver Jean-Jacques Hiblot
2019-09-10 13:27 ` [PATCH v6 3/4] dt-bindings: backlight: Add led-backlight binding Jean-Jacques Hiblot
2019-09-10 13:27 ` [PATCH v6 4/4] backlight: add led-backlight driver Jean-Jacques Hiblot
2019-09-10 13:32 ` Daniel Thompson
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